PITTSBURGH (KDKA) – The outbound Liberty Tunnel shut down at 8 p.m. and will remain closed for 16 days.

The tunnel is closed until July 28 so crews can repaint it, a project that was originally scheduled for last year.

Tens of thousands of Pittsburgh-area commuters will be affected by the closure.

PennDOT District 11 executive Dan Cessna says an around-the-clock closing for two weeks is the best option.

“We think it’s less inconvenient for motorists than to have months and months of single lane or detours during the night,” he said.

This particular job, however, brings a difficult detour with it.

“Because the detour does take a decent amount of time to travel through because you’re mixed with the traffic that goes through Mt. Washington to begin with,” said Cessna.

Officially, the detour will take you up the McArdle Roadway and down the backside of Mt. Washington to Route 51. It’s a one-lane detour almost the entire way, so PennDOT suggests if you have an alternative, use it.

The truck detour, on the other hand, is through the Fort Pitt Tunnel, which is where PennDOT expects many drivers will choose to go anyway. This additional detour will add to the “few tens of thousands of people who go through already,” Cessna says.

Once the outbound tunnel is finished, the inbound tunnel will also be painted, but dates for that have not been scheduled.

PennDOT says the inbound closure will take about the same amount of time.

Changes will also be going into effect on Route 51 and Route 88.

As you come northbound on 51 around the curve heading for 88, you will be diverted onto the two-lane “jug handle,” where you’ll slip around behind the Rite Aid. Drivers continuing north will stay to the right, while those heading for 88 will bear left and through the intersection.

“It’s going to allow us to begin replacement of all the culverts and bridges that go under Route 51, and that will begin phase construction,” Cessna said.

As the main line is being torn up and rebuilt, two lanes of southbound traffic will be maintained, although shifting around as needed.

“We will work in several lanes, we’ll move traffic, and we’ll just continue that phase through the remainder of this year.”

Don’t expect this new pattern to relieve the congestion, however.

“We would imagine, like any traffic switch, for the first few days, there could be some motorist confusion and could be additional backups,” Cessna said. “We think over time, we’ll actually see an improvement with the backups.”